The Dry Valleys in Antarctica are one of the strangest environments on Earth. High mountains surrounding the region create a rain shadow preventing moisture from the Antarctic ice sheet from crossing to reach the ocean. This environment creates cold, dry, landscapes with extreme aridity and almost stationary glaciers cemented to the valley's bedrock. The Dry Valleys have remained ice-free for perhaps 10 million years and are used as test laboratories for what Mars might be like.

Taylor Glacier is particularly odd as it has a waterfall that looks almost if bleeding, Blood Falls. The glacier is named for the Australian geologist who discovered it in 1911. Water samples from the falls have been analyzed and multiple microbial forms have been identified. The red derives from the bacteria that exist in a lake of ancient seawater under the glacier and which metabolize iron in the water. The trapped lake water is enriched by iron-containing salts that oxidize and turn blood red as it seeps down the 50 foot falls that emerge from a crack on the glacier's leading front.

Because of the Dry Valleys are ice-free, super-dry, and have been so for millions of years, they are considered a surrogate landscape for what Mars might be like today. Investigations of extremophiles, organisms that thrive in extreme environments, is one prime reason for ongoing bio-geological research there and to learn methods to do the same on Mars. A short video explores the idea of using extreme environments as natural laboratories.

Many Martian craters show signs of something seeping down the rim of crater walls, perhaps saline water from an underground aquifer. Salty water has a lower freezing point than fresh water and could exist as a liquid at the atmospheric temperature and pressure on Mars, especially at the equator. An example was observed by JPL's HiRize camera as it photographed the walls and cliffs in Newton Crater over a complete Martian year. A photo animation shows the seasonal color-change progression. It is still unknown the exact process being seen on Mars as other possible processees, such as movement of sand, could be underway.

There are many strange environments worth exploring and potential extreme organisms waiting to be discovered. Whether a bloody falls, a dry valley, or Mars canyon the mantra of discovery remains the same: follow the water!